#! /bin/sh
# Test for a bug in glibc's regex code as of 2015-09-19.
#
# Copyright 2015-2021 Free Software Foundation, Inc.
#
# Copying and distribution of this file, with or without modification,
# are permitted in any medium without royalty provided the copyright
# notice and this notice are preserved.

. "${srcdir=.}/init.sh"; path_prepend_ ../src

echo aa > in || framework_failure_

fail=0

grep -E 'b|(.)b|\1|b' in >out
status=$?
# POSIX isn't clear whether this regular expression should be invalid,
# (because the \1 is out of range for REs that could precede it)
# or valid but \1 should not match.  Allow either interpretation.
test $status -eq 2 || test $status -eq 1 || fail=1

grep -E '0|()0|\1|0' in >out
status=$?
test $status -eq 2 || test $status -eq 1 || fail=1

# This test is a reduced version of the one in Bug#27838.
# It triggers this glibc assertion failure:
# grep: regexec.c:1342: pop_fail_stack: Assertion `num >= 0' failed.
LC_ALL=C grep -E '(()x)|\2' in > out
status=$?
test $status -eq 2 || test $status -eq 1 || fail=1

Exit $fail
